1. Verify Relay Operation (Again):
* Visual Inspection: Carefully examine the relay itself. Look for any signs of damage, burnt contacts, or corrosion. A simple multimeter check for continuity across the appropriate terminals (refer to your owner's manual or a wiring diagram for the specific relay pinouts) can confirm if it's switching properly when the horn button is pressed.
* Power and Ground Checks: With the ignition on, test for power at the relay's input terminal (the one that gets power when the horn circuit is activated). Also, check for a good ground connection at the relay's ground terminal. You'll need a multimeter for these tests.
2. Test the Wiring Harness:
* Horn Button Continuity: With the ignition on, carefully disconnect the wiring harness connector at the steering wheel horn button. Using a multimeter, check for continuity between the terminals at the connector when you press the horn button. If there's no continuity, the problem is in the button or the wiring leading to it.
* Wiring to the Horns: Trace the wiring harness from the relay to the horns. Carefully check each wire for breaks, corrosion, or loose connections. Use your multimeter to test for continuity between the relay output terminal and the horns' positive terminals. You should have a complete circuit when the relay is activated. Also verify that the horns have a good ground.
* Ground Points: Make sure the ground wires connected to the horns and the horn relay are clean, secure, and making good contact with the vehicle's chassis. Corrosion on ground points is a common culprit.
3. Test the Horns Directly:
* Bypass the Wiring: This is the most direct test. Temporarily disconnect the wires leading to the horns. Using jumper wires and a 12V power source (like a battery), directly apply 12V power to each horn. If one or both horns sound, the problem lies in the wiring or relay circuit. If neither horn sounds, the horns are faulty.
4. Wiring Diagram:
* Essential Tool: Obtain a wiring diagram for your 1988 Chrysler Fifth Avenue. This diagram will show you the exact path of the wiring from the horn button, through the relay, to the horns. This is crucial for accurate troubleshooting. You can often find these online through repair manuals or automotive forums.
5. Professional Help:
* Consider a Mechanic: If you're uncomfortable working with car wiring or if you've checked everything and still can't find the problem, take your car to a qualified mechanic. They have the tools and expertise to diagnose and repair more complex electrical issues.
Important Safety Notes:
* Disconnect the Battery Negative Terminal: Before working on any car's electrical system, always disconnect the negative battery terminal to prevent accidental shorts or shocks.
* Work in a Well-Lit Area: Good lighting will make it easier to see the wiring and connections.
* Use Insulated Tools: Avoid using metal tools that could accidentally short circuit the wiring.
By systematically following these steps, you should be able to pinpoint the source of the problem with your Chrysler Fifth Avenue's horn. Remember the wiring diagram is your best friend in this process!
